Patent GB-1299433-A (GB)
Title: Improvements in disc brakes
Inventor: BROWN PETER WILLIAM
IPC: F16D65/56
Filed: 1969-01-25
Abstract: 1299433 Spot-type floating-caliper disc brakes; torque-taking GIRLING Ltd 23 Jan 1970 [25 Jan 1969 11 Feb 1969 18 April 1969 24 June 1969] 4326/69 31708/69 19799/69 and 7209/69 Heading F2E A spot-type disc brake having one of a pair of friction elements directly applied and the other carried by a sliding caliper for application by reaction has the caliper 10 mounted for sliding movement on a first pin 48, Fig. 7, arranged between the caliper and a fixed torque plate 44 adjoining the brake disc, and a second pin 46, Fig. 6, parallel to the first is secured to, e.g. the torque plate circumferentially spaced from the first pin and is located in an aperture 57 in the caliper by support means 56, the proportion of the drag force exerted on the "other" friction element and transferred to the torque plate by the second pin being pre-selectable during assembly of the brake. As shown, the caliper 10, Fig. 1, has a body portion 12, a bridge portion 14 and an end limb assembly 16, Fig. 2, the caliper straddling a brake disc 18, Fig. 4. End 16 has ears 20, Fig. 2, joined by a beam 22 having spaced lugs 24, Fig. 5, which locate a backplate 50 carrying a friction lining 52. The body portion 12 is internally formed to provide an hydraulic cylinder receiving a piston 26, Fig. 4, acting on a backplate 40 guided in an aperture of a torque plate 44 (see also Fig. 5); the backplate 40 carries a friction lining 42. The torque plate 44 carries a pair of circumferentially spaced and axially directed pins, 46, Fig. 6, and 48, Fig. 7,alongwhichrespectively slide the left hand part (as seen in Fig. 2) of the caliper 10, and a rearwardly extending boss 11 on the right hand part of the caliper, 48 is the "first" and 46 the "second" pin. The drag force experienced by pad 40, 42 is transferred directly to torque plate 44. The drag force experienced by pad 50, 52 is transferred through lugs 24, ears 20 and boss 11 and partly through pin 48 to the torque plate: the pin 46 transfers the remainder of the drag force and resists the tendency of caliper 10 to rotate as a result of the transfer of drag force. The pin 48, Fig. 7, is surrounded by a sleeve 54 radially spaced from it and held in compression by the pin; the interior of boss 11 is relieved between its end regions to improve the sliding contact between the boss and the sleeve. The pin 46, Fig. 6, is located in an eccentric bush 56 slidably located in an aperture 57 of the caliper body, the bush thus serving as support means. Tolerance in the circumferential spacing of pins 46, 48 may be accommodated during assembly of the brake by rotation of bush 56 within aperture 57 to shift the axis of the internal bore of bush 56 into line with the axis of pin 46. The bush 56 may be made of a non-corrodable material such as nylon; alternatively, it may be made of compressible or resilient material so that brake drag must be transmitted to the torque plate 44 by pin 48 and not pin 46. The pins may be fastened to the caliper in-  stead of to the torque plate. The sleeve-pin assembly 48, 54 may be  replaced by a different arrangement as follows.  A screw-threaded stud is screwed through an aperture in the torque plate from the side remote from the "sleeve" side until the stud head contacts the plate. A sleeve threaded in one end is introduced over the stud and threaded on to it until the unthreaded end of the sleeve engages in an annular groove in the torque plate. The spacing of pins 46 and 48 may be preselected so that a particular orientation of the eccentric bush relative to pin 46 has to be chosen.  Where the first pin 48 is also surrounded by  an eccentric bush, (not illustrated), the pin  spacing can be adjusted during assembly by rotating and then locking one bush, the sharing of the drag force being then determined by the resultant angular orientation of the second bush necessitated by this spacing.